Fix bugs in new extract_labels implementation

pygsti/circuits/circuit.py

@@ -1193,26 +1193,29 @@ def extract_labels(self, layers=None, lines=None, strict=True):
             Note that the returned circuit doesn't retain any original
             metadata, such as the compilable layer indices or occurence id.
         """
+        nonint_layers = not isinstance(layers, int)
 
         #Shortcut for common case when lines == None and when we're only taking a layer slice/index
         if lines is None and layers is not None:
             if self._static:
-                if isinstance(layers, int):
+                if not nonint_layers:
                     return self._labels[layers]
                 if isinstance(layers, slice) and strict is True:  # if strict=False, then need to recompute line labels
                     #can speed this up a measurably by manually computing the new hashable tuple value and hash
-                    new_hashable_tup = self._labels[layers] + ('@',) + self._line_labels
+                    if not self._line_labels in (('*',), ()):
+                        new_hashable_tup = self._labels[layers] + ('@',) + self._line_labels
+                    else:
+                        new_hashable_tup = self._labels[layers]
                     ret = Circuit.__new__(Circuit)
-                    return ret._copy_init(self._labels[layers], self._line_labels, not self._static, 
-                                          hashable_tup= new_hashable_tup, 
-                                          precomp_hash=hash(new_hashable_tup))
+                    return ret._copy_init(self._labels[layers], self._line_labels, not self._static, hashable_tup= new_hashable_tup, precomp_hash=hash(new_hashable_tup))
             else:
-                if isinstance(layers, int):
+                if not nonint_layers:
                     return self.layertup[layers]
                 if isinstance(layers, slice) and strict is True:  # if strict=False, then need to recompute line labels
                     return Circuit._fastinit(self._labels[layers], self._line_labels, not self._static)
         #otherwise assert both are not None:
 
+
         layers = self._proc_layers_arg(layers)
         lines = self._proc_lines_arg(lines)
         if len(layers) == 0 or len(lines) == 0:
@@ -1245,7 +1248,7 @@ def get_sslbls(lbl): return lbl.sslbls
                     ret_layer.append(l)
             ret.append(_Label(ret_layer) if len(ret_layer) != 1 else ret_layer[0])  # Labels b/c we use _fastinit
 
-        if not isinstance(layers, int):
+        if nonint_layers:
             if not strict: lines = "auto"  # since we may have included lbls on other lines
             # don't worry about string rep for now...